tests: prevent inclusion of time.h in baremetal compiles
baremetal compiles should not include time.h, as MBEDTLS_HAVE_TIME is
undefined. To test this, provide an overriding include directory that
has a time.h which throws a meaningful error if included.
Signed-off-by: Daniel Axtens <dja@axtens.net>
diff --git a/tests/include/baremetal-override/time.h b/tests/include/baremetal-override/time.h
new file mode 100644
index 0000000..40eed2d
--- /dev/null
+++ b/tests/include/baremetal-override/time.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright The Mbed TLS Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#error "time.h included in a configuration without MBEDTLS_HAVE_TIME"